Anglo-Saxon: god; ultimately from Sanskrit hu, to invoke, or hu, to sacrifice to

There is nothing better on this subject than the following passage from VenerableCardinalNewman‘s “Idea of a University,” discourse III

I mean then by the Supreme Being, one who is simply self-dependent, and the only Being who is such; moreover, that He is without beginning or Eternal, and the only Eternal; that in consequence He has lived a whole eternity by Himself; and hence that He is all-sufficient, sufficient for His own blessedness, and all-blessed, and ever-blessed. Further, I mean a Being, who, having these prerogatives, has the Supreme Good, or rather is the Supreme Good, or has all the attributes of Good in infinite intenseness; all wisdom, all truth, all justice, all love, all holiness, all beautifulness; who is omnipotent, omniscient, omnipresent; ineffably one, absolutely perfect; and such, that what we do not know and cannot even imagine of Him, is far more wonderful than what we do and can. I mean One who is sovereign over His own will and actions, though always according to the eternal Rule of right and wrong, which is Himself. I mean, moreover, that He created all things out of nothing, and preserves them every moment, and could destroy them as easily as He made them; and that, in consequence, He is separated from them by an abyss, and is incommunicable in all His attributes. And further, He has stamped upon all things, in the hour of their creation, their respective natures, and has given them their work and mission and their length of days, greater or less, in their appointed place. I mean, too, that He is ever present with His works, one by one, and confronts every thing He has made by His particular and most loving Providence, and manifests Himself to each according to its needs; and has on rational beings imprinted the moral law, and given them power to obey it, imposing on them the duty of worship and service, searching and scanning them through and through with His omniscient eye, and putting before them a present trial and a judgment to come.

Motion, i.e., the passing from power to act, as it takes place in the universe, implies a first unmoved Mover, who is God; else we should postulate an infinite series of movers, which is inconceivable.

For the same reason, efficient causes, as we see them operating in this world, imply the existence of a First Cause that is uncaused, i.e., that possesses in itself the sufficient reason for its existence; and this is God.

The fact that contingent beings exist, i.e., beings whose non-existence is recognized as possible, implies the existence of a necessary being, who is God.

The graduated perfections of being, actually existing in the universe, can be understood only by comparison with an absolute standard that is also actual, i.e., an infinitely perfect Being such as God.

The wonderful order or evidence of intelligent design, which the universe exhibits, implies the existence of a supramundane Designer, who is no other than God Himself.